Fears over Brucella re-emergence in southern US state
MedWire News: Feral pigs in the US state of North Carolina have tested positive for Brucella suis, an important pathogen that can be transmitted to humans, potentially leading to brucellosis.
This is the first time since screening began in 2004 that the bacteria has been detected in the state, and the discovery has raised concerns about the potential dangers to animal and human health.
"Now that exposure to Brucella suis has been found in North Carolina's feral pig populations, people need to take care when hunting, butchering, and cooking pigs," said Chris DePerno (North Carolina State University) in a press statement. "That means wearing gloves when field dressing feral pigs and cooking the meat to the proper temperature."
Writing in the Journal of Wildlife Diseases, DePerno and colleagues report findings from their serologic survey of feral swine (Sus scrofa) at 14 sites across the state of North Carolina. Thirteen of the sites were rural sites in the counties while one (Howell Woods) is a dedicated 2800-acre "environmental learning center."
"As feral swine (Sus scrofa) populations expand their range and the opportunity for feral swine hunting increases, there is increased potential for disease transmission that may impact humans, domestic swine, and wildlife," explain the researchers.
Between September 2007 and March 2010, 513 trapped and hunter-harvested swine were tested for exposure to four pathogens: B. suis, pseudorabies virus (PRV), classic swine fever virus (CSFV), and porcine circovirus type 2 (PCV-2).
B. suis antibodies were found in 9% of swine at Howell Woods, and in less than 1% of swine in the counties.
The prevalence of PCV-2 antibodies was 59% at Howell Woods (swine in the counties were not tested for this pathogen); neither PRV nor CSFV antibodies were found at any of the 14 sites.
DePerno et al write: "The detection of feral swine with antibodies to B. suis for the first time in North Carolina warrants increased surveillance of the feral swine population to evaluate speed of disease spread and to establish the potential risk to commercial swine and humans."
Control and eradication programs introduced in the late 1990s eliminated swine brucellosis from all commercial pig populations in the USA, the authors note.
"The biggest public health risk is to pork processors and hunters who field-dress feral pigs," said Suzanne Kennedy-Stoskopf, a co-author of the study and also from North Carolina State University.
She added: "Although cases of brucellosis are rare in the United States, people need to understand the clinical signs - like intermittent fevers and persistent headaches - and go to the doctor for diagnosis and treatment if they have these flu-like symptoms."
By Joanna Lyford